The expansion and contraction of soil is a significant factor in causing damage to the foundations of buildings and other structures. Such expansion and contraction results from changes in the moisture content of the soil and is particularly evident in clay soil. The changes in volume of the soil can place undesirable forces upon a foundation so as to cause structural damage.
Moisture content of soil can change for a variety of reasons. For example, water can be removed from the soil by the processes of transpiration via the presence of vegetation, evaporation and gravity. Such processes can create areas of localized water depletion as well as larger area wet/dry cycles that can cause a foundation to sag, crack and move, eventually leading to structural failure.
Attempts have been made in the prior art to stabilize the moisture content of soil around foundations:
U.S. Pat. No. 4,534,143 to Goines et al. discloses a soil moisture stabilization system comprising two circumferential zones around a house, where one circumferential zone is placed approximately three feet below the other.
U.S. Pat. No. 4,878,781 to Gregory et al. discloses a moisture control system comprising a plurality of supply pipes, accumulator pipes, and porous pipes for supplying water, storing water and allowing water to seep into surrounding soil.
U.S. Pat. No. 5,156,494 to Owens et al. discloses a soil moisture stabilization system that operates based on stress sensors placed on the foundation. Water is injected into the soil around a foundation when the stress sensors detect abnormal amounts of stress.
Despite these efforts, there remains a need for the development of an effective foundation and soil irrigation system. There is a particular need for a system that can optimize soil saturation and control specific sections around a structure that may need differing levels of moisture to achieve saturation.